arthur leigh allen: the prime and still only suspect at valljo, richard giaowski: his face matched the composit sketch and nacey slover(the switch board opearator at sfpd) said his voice exactly matched the voice she herd when the zodiac called to report the murder, rick marshal: never got his hand writting passed and was one of the prime suspects. if you would like to read more please visit zodiackiller.com (not my site)